Technetium or rhenium complexes, radiopharmaceutical products comprising them

ABSTRACT

The invention relates to a technetium or rhenium complex of formula (I): 
 
[M (R 1 CS 3 ) 2 L]  (I) 
 
in which M is Tc or Re, R 1  represents an alkyl, cycloalkyl, aralkyl or aryl group which is unsubstituted or substituted by one or more substituents chosen from halogen atoms, the hydroxyl group, alkyl groups and alkoxy groups, and L is a dithiolate ligand, with the exception of the ligand of formula R 2 CS 2  in which R 2  is identical to R 1 . 
The dithiolate ligand is preferably a dithiocarbamate.  
     The invention also relates to a radiopharmaceutical product comprising a complex of formula (I) with M representing  99 Tc,  186 Re or  188 Re.

A subject-matter of the present invention is novel technetium or rheniumcomplexes which can be used in radiopharmaceutical products fordiagnosis or therapy and which exhibit the advantage of being able tocomprise a biological vector.

It relates more particularly to technetium or rhenium complexes in whichthe metal is in the III oxidation state in the form of an M³+ ion.

Radiopharmaceutical products comprising these complexes areadvantageous, in particular when they comprise a biological vector whichrenders them suitable for the diagnosis or for the therapy of variouspathologies.

STATE OF THE PRIOR ART

Radiopharmaceuticals form a class of radioactive compounds generallycomposed of a γ- or β-emitting radioelement. These molecules may be usedalone, when they exhibit an intrinsic activity for the biologicaltarget, or else can be combined with an active biological molecule,conferring the desired tropism on the combination. Thus, the key pointof this discipline is based on the development of novelradiopharmaceuticals specific for an organ, for a physiological functionor for a pathology. For this, the isotope must first of all emit γphotons or β particles detectable by existing scintigraphic equipment.Among the radioelements most widely used in scintigraphy, technetium-99memerges as being the radioisotope of choice for nuclear medicine.

For some years, efforts have also been directed at the search for novelradiopharmaceuticals with a therapeutic purpose. The radiotracers usedin therapy are radiolabelled molecules designed to deliver, in the mostspecific way possible, therapeutic doses of ionizing rays to sites inthe body exhibiting physiological disorders (cancerous tumours). Thistechnique, referred to as “metabolic radiotherapy”, comes under nuclearmedicine. In this context, rhenium and in particular the ¹⁸⁶Re and ¹⁸⁸Reisotopes prove to be highly promising radioelements.

Radiopharmaceutical products based on technetium or on rhenium arealready known.

Thus, nitridobis(dithiocarbamato)Tc-99m complexes, in which thetechnetium is in the V oxidation state, have been provided in FR-A-2 698272 [1] as products for the in vitro labelling of blood cells and inparticular of leukocytes for the purpose of the anatomical locating ofinflammatory or infectious foci. These complexes correspond to theformula:(Tc≡N)L¹L²in which L¹ and L² represent two ligands of formula:

R¹ necessarily being an ethoxy group in at least one of the ligands L¹and L², whereas it can be an ethyl group or an ethoxy group in the otherof these ligands.

More recently, a rhenium complex with rhenium in the III oxidationstate, and therefore a complex which is more stable chemically andthermodynamically than the preceding complexes, has been provided by F.Mevellec et al. in Inorg. Chem. Comm., 2, 1999, 230-233 [2], also forthe in vitro labelling of leukocytes. This complex corresponds to theformula:[Re(S₃CPh)₂(S₂CPh)]and thus comprises three ligands, including two trithioperoxybenzoatesand one dithiobenzoate.

The complexes disclosed in the document [1] and the document [2] exhibita selective affinity with respect to leukocytes. Thus, placed in thepresence of a blood sample, they are capable of selectively binding tothe leukocytes present in this sample, this selectivity being expressedmore particularly with respect to granulocytes, in the case of thecomplexes of the document [1], and lymphocytes, in the case of thecomplex of the document [2].

On the other hand, they do not comprise a biological molecule capable ofacting as vector for them within a living organism and of directing themto a target other than an inflammatory or infectious focus.

Complexes based on rhenium sulphides have also been disclosed by Wei etal. in J. Am. Chem. Soc., 1990, 112, 6433-6434 [3], and by McConnachieand Stiefel in Inorg. Chem., 1997, 36, 6144-6145 [4] and Inorg. Chem.,1999, 38, 964-972 [5], but for use in the field of catalysis.

The Inventors therefore set themselves the target of providingtechnetium and rhenium complexes which, while exhibiting excellentchemical and thermodynamic stability, can comprise a biological vectorcapable of conferring on them a specificity with regard to specificcells, a specific physiological function or a specific pathology.

DESCRIPTION OF THE INVENTION

A specific subject-matter of the present invention is novel technetiumor rhenium complexes in which the technetium or rhenium is in the IIIoxidation state and which can additionally comprise a biological vectorsuitable for the diagnosis or therapeutic treatment to be carried out.According to the invention, these technetium or rhenium complexescorrespond to the formula (I):[M(R¹CS₃)₂L]  (I)in which M is Tc or Re, R¹ represents an alkyl, cycloalkyl, aralkyl oraryl group which is unsubstituted or substituted by one or moresubstituents chosen from halogen atoms, the hydroxyl group, alkyl groupsand alkoxy groups, and L is a dithiolate ligand, with the exception ofthe ligand of formula R²CS₂ in which R² is identical to R¹.

The complexes according to the invention thus exhibit the distinguishingfeature of comprising both a radioelement in the III oxidation state,which confers on them a highly satisfactory chemical and thermodynamicstability, and a dithiolate ligand L which comprises a group R²different from the group R¹ of the other two ligands.

It is thus possible, in the case where it is desired to couple thesecomplexes to a biological vector, to attach this vector to thisdithiolate ligand alone and not to all the ligands and, consequently, toprevent steric hindrance which would have the effect of preventing thevector from binding to its target.

In accordance with the invention, the dithiolate ligand can be chosenfrom the dithiocarbamate, xanthate, dithiophosphate, dithiophosphonate,dithiophosphinate, dithiocarboxylate, 1,2-dithiolate and 1,2-dithioleneligands.

The ligand L is preferably a dithiocarbamate of formula (II):

in which R³ and R⁴, which can be identical or different, represent ahydrogen atom, a C₁ to C₁₀, preferably C₁ to C₅, alkyl group, a C₆ toC₁₀ aryl group or a C₇ to C₁₂ aralkyl group, the alkyl, aryl or aralkylgroups optionally comprising one or more groups chosen from OH, SH,COOH, COOR, NH₂, NHR, NR₂, CONH₂, CONHR, CONR₂, NCSR and SCNR where theR groups, which can be identical or different, represent an alkyl oraryl group, groups capable of reacting with a biological molecule andgroups derived from a biological molecule which are optionally connectedto the alkyl, aryl or aralkyl group via a spacer, or in which R³ and R⁴form, together with the nitrogen atom to which they are bonded, aheterocycle having from 3 to 5 carbon atoms optionally comprisinganother heteroatom chosen from O, S and N, this heterocycle beingunsubstituted or substituted by one or more C₁ to C₁₀ alkyl, C₆ to C₁₀aryl or C₇ to C₁₂ aralkyl groups, the alkyl, aryl or aralkyl groupsoptionally comprising one or more groups chosen from OH, SH, COOH, COOR,NH₂, NHR, NR₂, CONH₂, CONHR, CONR₂, NSCR and SCNR where the R groups,which can be identical or different, represent an alkyl or aryl group,groups capable of reacting with a biological molecule and groups derivedfrom a biological molecule which are optionally connected to the alkyl,aryl or aralkyl group via a spacer.

The presence of such a ligand is particularly advantageous as it cancomprise either a group capable of reacting with a biological molecule,such as a hydroxyl, thiol, carboxylic acid, ester, amine, amide,thiocyanate or isothiocyanate group, or a group derived from abiological molecule which is optionally connected to the alkyl, aryl oraralkyl group of the ligand via a spacer.

This spacer can correspond to one of the following formulae:(CH₂)_(n), (CH₂O)_(n), (CH₂S)_(n) and (CH₂NR)_(n)in which R is as defined above and n is an integer ranging from 1 to 5.

The biological molecules capable of being attached to this ligand can behighly varied in nature. They can be, for example, antibodies, proteins,peptides, members of a ligands/receptors group, hormones or nucleicacids. Mention may be made, by way of examples, of molecules derivedfrom somatostatin, such as octreotide, labels, ligands of the serotoninreceptors, such as 1-(2-methoxyphenyl)piperazine, biotin, and the like.

In the case where the complexes comprise 1-(2-methoxyphenyl)piperazine,which has a high affinity for some cerebral receptors, theradiopharmaceutical products comprising such a complex will attachpreferentially to the receptors specific for this biological molecule.The concentration of receptors of this type in the various cerebralregions can thus be measured experimentally. These radiopharmaceuticalproducts can also be used for monitoring the inhibition of thesereceptors by other unlabelled molecules, for example medicaments ordrugs, by measuring the variation in the concentration of receptors ofthis type due to the unlabelled molecule.

Depending on the biological vector used, the complexes according to theinvention can be used as radiopharmaceuticals for detecting or treatingcancers, neurodegenerative diseases (Parkinson's disease, Alzheimer'sdisease or multiple sclerosis) or dysfunctions of the cardiovascularsystem.

In accordance with the invention, the group R¹ of the sulphur-comprisingligands R¹CS₃ and the ligand L are chosen so that the latter is a moreelectronegative molecule than the said sulphur-comprising ligands, thisbeing because the Inventors have found that this arrangement results inparticularly stable complexes being obtained.

The group R¹ of the sulphur-comprising ligands R¹CS₃ can be analiphatic, alkyl, cycloalkyl, aralkyl or aryl group. This group can beunsubstituted or substituted by one or more substituents chosen fromhalogen atoms, for example fluorine, the hydroxyl group, alkyl groupsand alkoxy groups.

The alkyl groups used for R¹ can be linear or branched C₁ to C₁₂ groups,preferably groups having 3 to 13 carbon atoms.

The cycloalkyl groups used for R¹ preferably have 3 to 7 carbon atoms,for example 6 carbon atoms.

The aryl groups used for R¹ can be of the phenyl or naphthyl type.

The aralkyl groups used for R¹ can be of the C₆H₅(CH₂)_(n) type with nranging from 1 to 3; preferably, n is equal to 1 or 2.

Preferably, according to the invention, the group R¹ is an optionallysubstituted aryl, aralkyl or cyclohexyl group.

Advantageously, when R¹ is an aryl group, it is chosen from the phenylgroup, the phenyl group substituted by one or more methyl, ethyl,propyl, butyl, ethoxy, methoxy and/or hydroxyl groups and/or by one ormore fluorine, chlorine, bromine and/or iodine atoms, the naphthyl groupand the naphthyl group substituted by a group chosen from alkyl oralkoxy groups and halogen atoms.

In the case where R¹ is an aralkyl group, the latter is advantageouslythe benzyl or phenethyl group.

In the ligand L of dithiocarbamate type, R³ and R⁴ are chosen accordingto the use envisaged for the complex produced.

Mention may be made, as example of dithiocarbamate ligands used in theinvention, of the ligands in which R³ and R⁴ have the meanings givenbelow:

-   -   1) R³ and R⁴ are identical and represent a methyl, ethyl or        ethoxy group;    -   2) R³ is the ethyl group and R⁴ is the hydroxyethyl group;    -   3) R³ and R⁴ form, with the nitrogen atom to which they are        bonded, a piperidine, pyrrolidine, pyridine, piperazine,        ethylpiperazine or morpholine ring;    -   4) R³ is a hydrogen atom and R⁴ represents the group of formula        (III):        in which n is an integer ranging from 1 to 6, preferably equal        to 2; and    -   5) R³ and R⁴ form, together with the nitrogen atom to which they        are bonded, the group of formula (X):        in which n is an integer ranging from 1 to 6, preferably equal        to 2.

The technetium and rhenium complexes described above can be used inradiopharmaceutical products.

Consequently, another subject-matter of the invention is aradiopharmaceutical product comprising a technetium or rhenium complexas described above in which M is ^(99m)Tc, ¹⁸⁶Re or ¹⁸⁸Re.

Another subject-matter of the invention is a process for the preparationof the technetium or rhenium complexes corresponding to formula (I).

According to a first embodiment of this process, the technetium orrhenium complex of formula (I) is obtained by carrying out the followingstages:

-   -   reacting a salt of formula (IVa) or (IVb):        (MO₄)⁻Z_(a) ⁺  (IVa)        [MOCl₄]⁻Z_(a) ⁺  (IVb)        in which M is as defined above and Z_(a) ⁺ is a pharmaceutically        acceptable cation, with a reducing agent, and    -   adding, to the reaction mixture, a dithiocarboxylate of formula        (V):        (R¹CS₂)⁻Z_(b) ⁺  (V)        in which R¹ is as defined above and Z_(b) ⁺ represents a        pharmaceutically acceptable cation, and a salt L⁻X⁺ where L is        as defined above and X⁺ is a cation chosen from sodium and        potassium.

According to a second embodiment of the process of the invention, thecomplexes of formula (I) are obtained from a technetium or rheniumcomplex of formula (VI):[M(R¹CS₃)₂(R¹CS₂)]  (VI)in which M and R¹ are as defined above, by bringing this complex intocontact with a salt L⁻X⁺, where L is as defined above and X⁺ is a cationchosen from sodium and potassium, in order to exchange the ligand R¹CS₂with the ligand L.

The complexes of formula (VI) used as starting materials in this secondembodiment of the process of the invention can be prepared by a processcomprising the following stages:

-   -   reacting a salt of formula (IVa):        (MO₄)⁻Z_(a) ⁺  (IVa)        in which M is as defined above and Z_(a) ⁺ is a pharmaceutically        acceptable cation, with a reducing agent, and    -   adding, to the reaction mixture, a dithiocarboxylate of formula        (V):        (R¹CS₂)⁻Z_(b) ⁺  (V)        in which R¹ is as defined above and Z_(b) ⁺ represents a        pharmaceutically acceptable cation.

In these various methods of preparation, the pharmaceutically acceptablecations used for Z_(a) ⁺ can be alkali metal or alkaline earth metalions, for example sodium, ammonium ions and quaternary ammonium ions,such as NH₄ and NBu₄, with Bu representing the butyl group.

The pharmaceutically acceptable cations used for Z_(b) ⁺ can be chosenfrom MgX⁺, where X is a halogen atom, such as Br or Cl, quaternaryammonium cations and alkali metal ions, such as sodium.

The quaternary ammonium cations can be, for example, of the NR₄ type,where R is an alkyl group, for example methyl. Use may also be made ofquaternary ammonium cations of the piperidinium type of formula C₅H₁₀NH₂⁺.

In both embodiments of the process of the invention, the reducing agentused can be of various types. Use may in particular be made of areducing agent composed of a tin salt in combination with a complexingagent having a higher complexing power for the tin than that of thedithiocarboxylate.

This complexing agent can be of the phosphonate, polyphosphate andpolyaminocarboxylic acid type. Mention may be made, as examples of suchcomplexing agents, of ammonium or alkali metal or alkaline earth metalpyrophosphates, ammonium or alkali metal or alkaline earth metalglucoheptonates, ammonium or alkali metaldiethylenetriaminepentaacetates, ammonium or alkali metal or alkalineearth metal ethylenediaminetetraacetates, ammonium or alkali metal oralkaline earth metal 1,2-diaminopropane-N,N,N′,N′-tetraacetates,ammonium or alkali metal or alkaline earth metal gluconates, ammonium oralkali metal or alkaline earth metal methylenediphosphonates, ammoniumor alkali metal or alkaline earth metal hydroxymethylenediphosphonates,and ammonium or alkali metal or alkaline earth metal citrates.

Use may be made in the invention, by way of example, of a tin saltcomposed of tin chloride in combination with a complexing agent chosenfrom calcium gluconate, 1,2-diaminopropane-N,N,N′,N′-tetraacetic acidand a dithiocarbazate DTCZ.

Use may also be made, according to the invention, of reducing agentscomposed of a phosphine or of one of its derivatives in combination withhydrochloric acid.

Mention may be made, as example of phosphine and of phosphinederivative, of triphenylphosphine and sodiumtriphenylphosphine-tri-meta-sulphonate P(C₆H₄SO₃)₃Na₃.

In the process of the invention, the metal M, which was initially in theVII oxidation state, is reduced to the III oxidation state, while aportion of the dithiocarboxylate ligand is oxidized totrithioperoxycarboxylate.

The amounts of reducing agent used in this process are chosen accordingto the amount of pertechnetate or perrhenate initially introduced.

In the case of the pertechnetate Tc^(99m), for activities of 30 MBq to 4GBq, use may be made of amounts of reducing agent ranging from 0.01 to 1mg in the case of SnCl₂.2H₂O, in the presence of an excess of complexingagent with respect to the tin chloride.

When a triphenylphosphine is used as reducing agent, the amounts usedare of the order of 0.1 to 5 mg, in the case of pure triphenylphosphine,and of 0.2 to 10 mg, in the case of sodiumtriphenylphosphine-tri-meta-sulphonate. An aqueous HCl solution is addedwith these reducing agents in order to obtain 1×10⁻² to 1×10⁻¹ mol/l ofHCl in the reaction medium.

Despite the similarity in the chemical properties between thepertechnetate and the perrhenate, it is known that, for the reductionreaction, the latter ion requires larger amounts of reducing agent thanthose employed for the pertechnetate ion.

Furthermore, in the case where the radioactive metal is rhenium-186, anisotope having a low specific activity, the amount of perrhenate used isgreater in order to obtain the same activity; consequently, to reducethis species, larger amounts of reducing agent will be used than in thecase of the rhenium-188 isotope.

Thus, use may be made of 0.1 to 5 mg of reducing agent in the case ofSnCl₂.2H₂O, 0.1 to 10 mg in the case of pure triphenylphosphine and 0.2to 20 mg in the case of sodium triphenylphosphine-tri-meta-sulphonate.

A sufficient amount of dithiocarboxylate and optionally of L⁻X⁺ salt,preferably dissolved in physiological saline, is subsequently added tothe reaction medium. The reaction of the ligand(s) with thepertechnetate or perrhenate is carried out under hot conditions, forexample at a temperature of 100° C.

In the first embodiment of the process of the invention, the operationis carried out in an organic solvent, such as dichloromethane, or inwater by adding, to the solution of the salts of the ligand L and ofR¹CS₂, a solution of the salt of formula (MO₄)⁻Z_(a) ⁺ in the samesolvent.

In the second embodiment of the process of the invention, an exchangereaction is carried out between the technetium or rhenium complex offormula (VI) and a salt of the ligand L. For this exchange reaction, asalt of the ligand L in solution in an organic solvent, such asmethanol, or in water is added to the complex of formula (VI) insolution in an organic solvent, such as dichloromethane, or insuspension in water.

According to the invention, when the ligand L comprises a group capableof reacting with a biological molecule, the process can comprise anadditional stage consisting in reacting the complex formed above with abiological molecule in order to attach it to the ligand L via thisgroup. The biological molecule can also be introduced onto the ligand Lbeforehand, in order to directly obtain a complex comprising thisbiological molecule.

A further subject-matter of the invention is a kit for the preparationof a radiopharmaceutical product comprising a complex of formula (I):[M(R¹CS₃)₂L]  (I)in which M is ^(99m)Tc, ¹⁸⁶Re or ¹⁸⁸Re, R¹ represents an alkyl,cycloalkyl, aralkyl or aryl group which is unsubstituted or substitutedby one or more substituents chosen from halogen atoms, the hydroxylgroup, alkyl groups and alkoxy groups, and L is a dithiolate ligand,with the exception of the ligand of formula R²CS₂ in which R² isidentical to R¹, characterized in that it comprises:

-   -   a first bottle comprising a tin salt in combination with a        complexing agent, or a phosphine and hydrochloric acid,    -   a second bottle comprising a dithiocarboxylate of formula        (R¹CS₂)⁻Z_(b) ⁺ in which R¹ is as defined above and Z_(b) ⁺        represents a pharmaceutically acceptable cation, and    -   a third bottle comprising a salt L⁻X⁺ where L is as defined        above and X⁺ is a cation chosen from sodium and potassium.

When the kit is intended to implement the first embodiment of theprocess of the invention, the first and the second bottles can bereplaced by a single bottle and, in this case, the kit comprises:

-   -   a first bottle comprising a tin salt in combination with a        complexing agent, or a phosphine and hydrochloric acid, and    -   a second bottle comprising a dithiocarboxylate of formula        (R¹CS₂)⁻Z_(b) ⁺ in which R¹ is as defined above and Z_(b) ⁺        represents a pharmaceutically acceptable cation, and a salt L⁻X⁺        where L is as defined above and X⁺ is a cation chosen from        sodium and potassium.

Generally, in both embodiments of the kit, the first bottle comprisestin chloride SnCl₂.2H₂O in combination with a complexing agent chosenfrom calcium gluconate, 1,2-diaminopropane-N,N,N′,N′-tetraacetic acidand a dithiocarbazate DTCZ. According to an alternative implementation,this first bottle comprises triphenylphosphine or sodiumtriphenylphosphine-tri-meta-sulphonate, and hydrochloric acid.

In both embodiments of the kit, the latter can additionally comprise abottle comprising a biological molecule.

The radiopharmaceutical products comprising the complexes of theinvention are particularly advantageous as they can be adapted tovarious pathologies, depending on the nature of the ligand L and of thebiological molecule with which it is combined.

Thus, it is possible to obtain, in accordance with the invention,radiopharmaceutical products labelled with a suitable biological vector.

Furthermore, such radiopharmaceutical products with technetium ^(99m)Tcor with rhenium ¹⁸⁶Re or ¹⁸⁸Re can be prepared in less than one hourfrom a kit comprising three bottles respectively comprising the reducingagent (tin salt-gluconate), the dithiocarboxylate (R¹CS₂)⁻Z_(b) ⁺ andthe salt of the ligand L, for example a dithiocarbamate.

Other characteristics and advantages of the invention will become moreclearly apparent on reading the following examples, given, of course, byway of illustration and without implied limitation.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The following Examples 1 to 11 illustrate the preparation of rhenium andtechnetium complexes in accordance with the invention.

Examples 1 to 6 illustrate the first embodiment of the process of theinvention. Examples 7 to 11 illustrate the second embodiment of theprocess of the invention.

Examples 12 to 14 illustrate the preparation of dithiocarbamate ligandsof use in the preparation of the complexes of the invention.

EXAMPLE 1 Preparation ofbis(trithioperoxybenzoato)-(diethyldithiocarbamato)rhenium (III)[Re(PhCS₃)₂(Et₂NCS₂)]

A mixture of 0.407 g (1.7 mmol) of piperidinium phenyldithiocarboxylatesalt and 0.383 g (1.7 mmol) of sodium diethyldithiocarbamate in theminimum amount of dichloromethane (20 ml) is added dropwise to asolution comprising 0.100 g (0.170 mmol) of [ReOCl₄][NBu₄] indichloromethane (5 ml). After stirring for 6 hours at ambienttemperature, the solvent is evaporated and the residue, taken up indichloromethane, is chromatographed on a column of silica gel (eluent:petroleum ether/dichloromethane: 70/30) and then recrystallized from apetroleum ether/dichloromethane mixture.

0.090 g of complex is thus obtained in the form of khaki green crystals(yield of 75%).

The characteristics of this complex are as follows:

-   -   M=705.11;    -   melting point M.p.=164-166° C.;    -   R_(f)=0.50 (petroleum ether/CH₂Cl₂: 70/30);

¹H NMR (CDCl₃): 1.19 (t, J=7.1 Hz, 6H, CH₃), 3.60 (m, 4H, CH₂), 7.31 (t,J=8.1 Hz, 2H, H₈), 7.53 (t, J=8.1 Hz, 4H, H₇), 8.07 (d, J=8.6 Hz, 4H,H₆).

¹³C NMR (CDCl₃): 12.8 (CH₃), 44.4 (CH₂), 128.1 and 132.4 (C₆ and C₇),132.8 (C₈), 134.9 (C₅), 204.5 (NCS₂), 233.4 (CS₃).

Mass spectrometry (FAB): m/z=704.7: [M⁺.]; 551.8: [M^(+•)-(PhCS₂)].Elemental analysis: empirical formula: C₁₉H₂₀NS₈Re Experimental: %C=32.44 % H=2.87 % S=36.41 Calculated: % C=32.35 % H=2.86 % S=36.36

Infrared (KBr disc): 2 963 (w), 2 921 (w), 2 852 (w), 1 504 (s), 1 482(m), 1 454 (m), 1 440 (s), 1 377 (w), 1 354 (w), 1 300 (w), 1 275 (m), 1241 (m), 1 208 (m), 1 179 (w), 1 149 (m), 1 078 (w), 1 028 (w), 1 001(s), 990 (s, ν_(C═S)) 908 (m), 755 (s), 687 (s), 544 (s, ν_(S—S)) 454(m), 399 (m, ν_(Re—S)).

EXAMPLE 2 Preparation ofbis(trithioperoxybenzoato)-(dimethyldithiocarbamato)rhenium(III)[Re(PhCS₃)₂(Me₂NCS₂)]

The same procedure as in Example 1 is followed in preparing thiscomplex, using sodium dimethyldithiocarbamate instead of sodiumdiethyldithiocarbamate. 0.080 g of green crystals of the complex(yield=69% ) is thus obtained. The characteristics of the complex are asfollows:

-   -   M=677.05;    -   M.p.=160-162° C.;    -   R_(f)=0.45 (petroleum ether/CH₂Cl₂: 70/30);

¹H NMR (CDCl₃): 3.24 (s, 6H, CH₃), 7.31 (t, J=7.6 Hz, 2H, H_(ar)), 7.52(t, J=8.1 Hz, 4H, H_(ar)), 8.07 (dd, J=8.1 Hz and J=2.5 Hz, 4H, H_(ar)).

¹³C NMR (CDCl₃): 39.5 (CH₃), 128.1 and 132.4 (CH_(o and m)), 132.9(CH_(p)), 134.9 (C_(q)), 207.1 (NCS₂), 233.8 (CS₃). Elemental analysis:empirical formula: C₁₇H₁₆NS₈Re Experimental: % C=30.21 % H=2.40 %S=37.85 Calculated: % C=30.16 % H=2.38 % S=37.89

Infrared (KBr disc): 1 594 (w), 1 569 (w), 1 533 (w), 1 481 (m), 1 441(m), 1 393 (s), 1 329 (w), 1 261 (m), 1 252 (m), 1 148 (m), 1 098 (w), 1027 (w), 1 009 (m), 990 (s, ν_(C═S)) 775 (s), 681 (s), 544 (s, ν_(S—S))454 (m), 399 (m, ν_(Re—S)).

EXAMPLE 3 Preparation ofbis(trithioperoxybenzoato)-(N-piperidyldithiocarbamato)rhenium(III)[Re(PhCS₃)₂(C₅H₁₀NCS₂)]

The same procedure as in Example 1 is followed in preparing this rheniumcomplex, using piperidinium piperidyldithiocarbamate instead of sodiumdiethyldithiocarbamate.

The piperidyldithiocarbamate is obtained in the following way.

4.25 g (0.050 mol, 5 ml) of piperidine are dissolved in 100 ml of etherin a two-necked flask and 2.40 g (0.060 mol) of NaOH are added to thesolution with stirring. The mixture obtained is cooled to −15° C. usinga bath of liquid nitrogen and 3.95 g (0.052 mol, 3.2 ml) of carbondisulphide are added dropwise to the solution. The mixture is maintainedat −15° C. for 30 minutes. After returning to ambient temperature withstirring, the solid obtained is filtered off, washed with ether anddried under vacuum, and then recrystallized from an isopropanol/ether(1:2) mixture.

5.03 g of white crystals, comprising 41% of piperidiniumpiperidyldithiocarbamate and a very small amount of sodiumpiperidyldithiocarbamate, are thus obtained.

The characteristics of the piperidinium salt are as follows:

¹H NMR: 1.55 (m, 8H, 2H₃, 4H₅ and 2H₆), 1.69 (m, 4H, 4H₂), 3.07 (t, 4H,H₄, J₄₋₅=5.6 Hz), 4.17 (t, 4H, H₁, J₁₋₂=5.3 Hz).

¹³C NMR: 21.1 (C₆), 21.9 (C₃), 23.3 (C₅), 25.2 (C₂), 44.2 (C₄), 52.6(C₁), 202.2 (C—S).

Infrared spectrum (ν in cm⁻¹): 2 930 (s, CH₂), 2 852 (m, CH₂), 1 449 (w,CH₂), 1 409 (s, C—N), 1 218 (s, C═S).

By following the procedure of Example 1 and by using thisdithiocarbamate, 0.085 g of complex in the form of green crystals(yield=70% ) is obtained.

The characteristics of the complex are as follows:

-   -   M=716.96;    -   M.p.=196-198° C.;    -   R_(f)=0.46 (petroleum ether/CH₂Cl₂: 70/30);

¹H NMR (CDCl₃): 1.60 (s, br, 4H, CH₂), 1.65 (s, br, 2H, CH₂), 3.74 (s,br, 4H, NCH₂), 7.31 (t, J=7.6 Hz, 2H, H_(ar)), 7.54 (t, J=7.6 Hz, 4H,H_(ar)), 8.07 (d, J=8.1 Hz, 4H, H_(ar)).

¹³C NMR (CDCl₃): 23.8 (CH₂), 25.3 (CH₂), 47.6 (CH₂), 128.1 and 132.4(CH_(ar)), 132.9 (CH_(ar)), 134.9 (C_(ar)), 203.5 (NCS₂), 233.5 (CS₃).

Mass spectrometry (FAB): m/z=716.891914: [M⁺.]; 563.9: [M⁺.-(PhCS₂)];531.9: [Re—(PhCS₃)]. Elemental analysis: empirical formula: C₂₀H₂₀NS₈ReExperimental: % C=33.29 % H=2.79 % S=35.81 Calculated: % C=33.50 %H=2.81 % S=35.77

Infrared (KBr disc): 2 963 (w), 2 921 (w), 2 852 (w), 1 498 (s), 1 441(s), 1 261 (s), 1 243 (m), 1 096 (s), 1 023 (s), 800 (s, νC═S), 755 (m),678 (m), 544 (s), ν_(S—S)) 454 (m), 399 (m, ν_(Re—S)).

EXAMPLE 4 Preparation ofbis(trithioperoxybenzoato)-(N-morpholinodithiocarbamato)rhenium(III)[Re(PhCS₃)₂(O(CH₂CH₂)₂NCS₂)]

The same procedure as in Example 1 is followed, using sodiummorpholinodithiocarbamate instead of sodium diethyldithiocarbamate.

0.069 g of complex is thus obtained in the form of green crystals(yield=55% ).

The characteristics of the complex are as follows:

-   -   M=719.04;    -   M.p.>260°0 C.;    -   R_(f)=0.16 (petroleum ether/CH₂Cl₂: 70/30);

¹H NMR (CDCl₃): 3.63 (t, J=4.1 Hz, 4H, NCH₂), 3.77 (t, J=4.0 Hz, 4H,OCH₂), 7.48 (m, 6H, H_(ar)), 8.02 (dd, J=1.0 and 8.4 Hz, 4H, H_(ar)).

¹³C NMR (CDCl₃): 46.1 (NCH₂), 65.9 (OCH₂), 128.1, 132.5 and 133.0(CH_(ar)), 134.9 (C_(ar)), 205.8 (NCS₂), 248.6 (CS₃). Elementalanalysis: empirical formula: C₁₉H₁₈NOReS₈. Experimental: % C=32.02 %H=2.55 % S=35.81 Calculated: % C=31.70 % H=2.50 % S=35.70

Infrared (KBr disc): 1 492 (s), 1 442 (m), 1 428 (m), 1 298 (w), 1 268(w), 1 235 (s), 1 183 (w), 1 114 (w), 1 028 (w), 1 008 (s, ν_(C—S)), 994(m, ν_(C—S)), 908 (w), 882 (w), 757 (m), 680 (w), 551 (w), 544 (s,ν_(S—S)), 454 (m), 399 (m, ν_(Re—S)).

EXAMPLE 5 Preparation ofbis(trithioperoxybenzoato)-(N-ethyl-N-(2-hydroxyethyl)dithiocarbamato)rhenium(III)[Re(PhCS₃)₂( (HOCH₂CH₂)N(Et)CS₂)]

The same procedure as in Example 1 is followed, except that sodiumN-ethyl-N-(2-hydroxyethyl)dithiocarbamate is used instead of sodiumdiethyldithiocarbamate.

0.063 g of complex is thus obtained in the form of green crystals(yield=50% ).

The characteristics of this complex are as follows:

-   -   M=721.06;    -   M.p.=196-198° C.;    -   R_(f)=0.46 (petroleum ether/CH₂Cl₂: 70/30);

¹H NMR (CDCl₃): 0.81 (t, J=7.1 Hz, 3H, CH₃), 1.60 (s, br, 2H, NCH ₂CH₃),1.65 (s, br, 2H, CH ₂CH₂N), 3.67 (q, J=7.0 Hz, 2H, OCH ₂CH₂N), 7.26 (t,J=7.6 Hz, 2H, H_(ar)), 7.47 (t, J=7.6 Hz, 4H, H_(ar)), 8.01 (d, J=8.1Hz, 4H, H_(ar)).

¹³C NMR (CDCl₃): 23.8 (CH₃), 24.6 (NCH₂), 25.3 (NCH₂), 47.6 (OCH₂),128.1 and 132.4 (CH_(ar)), 132.9 (CH_(ar)), 134.9 (C_(ar)), 203.5(NCS₂), 233.5 (CS₃). Elemental analysis: empirical formula:C₁₉H₂₀NORes₈. Experimental: % C=31.51 % H=2.79 % S=35.77 Calculated: %C=31.60 % H=2.80 % S=35.60

Infrared (KBr disc): 2 963 (w), 2 921 (w), 2 852 (w), 1 499 (s), 1 482(m), 1 442 (s), 1 261 (w), 1 245 (s), 1 180 (w), 1 118 (w), 1 029 (w), 1004 (s, ν_(C═S)) 992 (s, νf_(C—S)) 757 (s), 580 (m), 544 (s, ν_(S—S))454 (m), 399 (m, ν_(Re—S).)

EXAMPLE 6 Preparation ofbis(trithioperoxy-naphthoato)(diethyldithiocarbamato)rhenium(III)[Re(C₁₀H₇CS₃)₂(Et₂NCS₂)]

The same procedure as in Example 1 is followed, except that piperidiniumdithionaphthoate is used instead of the piperidiniumphenyldithiocarboxylate salt.

0.70 g of the complex is thus obtained in the form of green crystals(yield=50% ).

The characteristics of this complex are as follows:

-   -   M=805.18;    -   M.p.=218° C.;    -   R_(f)=0.53 (petroleum ether/CH₂Cl₂: 70/30);

¹H NMR (CDCl₃): 1.20 (t, J=7.1 Hz, 6H, CH₃), 3.80 (q, J=7.1 Hz, 4H, NCH₂), 7.85 (dd, J=1.5 Hz and J=6.9 Hz, 2H, H_(ar)), 7.90 (t, J=6.6 Hz andJ=7.9 Hz, 2H, H_(ar)), 7.98 (t, J=7.4 Hz and J=7.9 Hz, 2H, H_(ar)), 8.07(d, J=6.9 Hz, 2H, H_(ar)), 8.20 (d, J=8.1 Hz, 2H, H_(ar)), 8.25 (d,J=7.6 Hz, 2H, H_(ar)), 8.44 (d, J=8.1 Hz, 2H, H_(ar)).

¹³C NMR (CDCl₃): 12.8 (CH₃), 44.6 (CH₂), 125.8, 126.4, 127.3, 128.5,130.4, 130.5, 131.2, 132.9, 133.5 and 133.5 (10 C_(ar)), 207.1 (CS₂),233.6 (CS₃). Elemental analysis: empirical formula: C₂₇H₂₄NReS₈.Experimental: % C=40.44 % H=3.02 % S=31.96 Calculated: % C=40.30 %H=3.00 % S=31.90

Infrared (KBr disc): 1 505 (s), 1 456 (w), 1 436 (m), 1 390 (w), 1 352(w), 1 276 (m), 1 240 (m), 1 208 (w), 1 152 (w), 1 076 (w), 1 002 (s,ν_(C═S)), 856 (w), 796 (s), 770 (s), 453 (w), 428 (w), 544 (s, ν_(S—S))454 (m), 399 (m, ν_(Re—S).)

EXAMPLE 7 Preparation ofbis(trithioperoxybenzoato)-(diethyldithiocarbamato)rhenium(III)[Re(PhCS₃)₂(Et₂NCS₂)]

In this example, the complex of Example 1 is prepared by following thesecond embodiment of the process of the invention.

a) Preparation of the Complex [Re(S₃CPh)₂(S₂CPh)]

0.300 g (1.25 mmol) of piperidinium phenyldithiocarboxylate salt,dissolved in the minimum amount of dichloromethane (30 ml), is addeddropwise to solution comprising 0.560 g (0.208 mmol) of [ReO₄][NH₄],0.118 g (0.622 mmol) of SnCl₂.2H₂O and 5.0 g (27.1 mmol) of citric acidin dichloromethane (10 ml). After stirring for 2 hours at ambienttemperature, the solvent is evaporated and the residue, taken up indichloromethane, is chromatographed on a column of silica gel (eluent:petroleum ether/dichloromethane: 60/40) and then recrystallized from apetroleum ether/dichloromethane mixture.

0.090 g of complex is thus obtained in the form of green crystals(yield=61% ).

The characteristics of this complex are as follows:

-   -   M=709.90;    -   M.p.=205-207° C.;    -   R_(f)=0.50 (petroleum ether/CH₂Cl₂: 80/20);

¹H NMR (CDCl₃): 7.29 (m, J=3.5 Hz, 5H, H₄, H₅ and H₁₀), 7.44 (t, J=8.0Hz, 4H, H₉), 7.63 (dd, J=8.0 Hz and J=2.5 Hz, 2H, H₃), 7.96 (dd, J=8.5Hz and J=1.5 Hz, 4H, H₈).

¹³C NMR (CDCl₃): 123.7 (C₃), 126.4 (C₄), 127.2 (C₈), 130.8 (C₉), 132.1(C₅), 132.3 (C₁₀), 133.9 (C₇), 141.7 (C₂), 232.8 (CS₂ ₆), 237.6 (CS₂ ₁).

Mass spectrometry (FAB): m/z=709.8527: [M⁺.]; 556.9: [M-(PhCS₂)]⁺;493.0: [Re(PhCS₂)₂]⁺. Elemental analysis: empirical formula: C₂₁H₁₅S₈Re.Experimental: % C=35.34 % H=2.13 % S=35.99 Calculated: % C=35.35 % H2.13 % S=36.03

Infrared (KBr disc): 1 482 (m), 1 442 (s), 1 332 (m), 1 311 (w), 1 263(s), 1 234 (w), 1 179 (w), 1 156 (w), 1 096 (m), 1 028 (m), 997 (s,ν_(C—S)), 947 (w), 908 (w), 802 (m), 755 (s), 681 (w), 652 (w), 544 (s,ν_(S—S)) 454 (m), 399 (m, ν_(Re—S)).

b) Preparation of the Final Complex

0.032 g (1.41 mmol) of sodium diethyldithiocarbamate, in the minimumamount of methanol (10 ml), is added dropwise to a solution of 0.020 g(0.028 mmol) of [Re(S₃CPh)₂(S₂CPh)] in dichloromethane (10 ml). Afterstirring for 1 hour at ambient temperature, the solvent is evaporatedand the residue, taken up in dichloromethane, is chromatographed on acolumn of silica gel (eluent: petroleum ether/dichloromethane: 70/30)and then recrystallized from a petroleum ether/dichloromethane mixture.

0.020 g of complex is thus obtained in the form of khaki green crystals,which corresponds to a quantitative yield.

The characteristics of the complex are identical to those in Example 1.

EXAMPLE 8 Preparation ofbis(trithioperoxybenzoato)-(dimethyldithiocarbamato)rhenium(III) [Re(PhCS₃)₂(Me₂NCS₂)]

In this example, the same procedure as in Example 7 is followed, usingsodium dimethyldithiocarbamate instead of sodium diethyldithiocarbamate.

0.015 g of complex is thus obtained in the form of green crystals, whichcorresponds to a yield of 79%.

The characteristics of the complex are identical to those in Example 2.

EXAMPLE 9 Preparation ofbis(trithioperoxybenzoato)-(N-piperidyldithiocarbamato)rhenium(III)[Re(PhCS₃)₂(C₅H₁₀NCS₂)]

In this example, the same procedure as in Example 7 is followed forpreparing the complex of Example 3, using piperidyldithiocarbamateinstead of diethyldithio-carbamate.

0.015 g of complex is thus obtained in the form of green crystals, whichcorresponds to a yield of 75%.

The characteristics of the complex are identical to those in Example 3.

EXAMPLE 10 Preparation ofbis(trithioperoxybenzoato)-(diethyldithiocarbamato)technetium(III)[Tc(PhCS₃)₂(Et₂NCS₂)]

In this example, the second embodiment of the process of the inventionis followed for preparing the technetium complex.

a) Preparation of the Complex [Tc(PhCS₃)₂(PhCS₂)]

0.4 to 0.8 GBq of sodium pertechnetate NaTcO₄ is added to a flaskcomprising 75.0 mg of calcium gluconate, 0.75 mg of SnCl₂.2H₂O and 25.0mg of sodium chloride dissolved in 10 ml of physiological saline. Themixture is stirred at ambient temperature for 10 minutes, then 20 mg ofsodium dithiobenzoate NaPhCS₂, dissolved in 1.0 ml of physiologicalsaline under warm conditions, are added and the solution is heated at100° C. for an additional 15 minutes.

The complex obtained has the following characteristics:

-   -   R_(f)=0.62 (petroleum ether/CH₂Cl₂: 70/30).

b) Preparation of the Final Complex

0.098 g (0.410 mmol) of sodium diethyldithiocarbamate in the minimumamount of methanol (10 ml) is added dropwise to a solution of 0.051 g(0.082 mmol) of [Tc(S₃CPh)₂(S₂CPh)] in dichloromethane (10 ml). Afterstirring for 1 hour at ambient temperature, the precipitate is filteredoff, washed several times with methanol, chromatographed on a column ofsilica gel (eluent: petroleum ether/dichloromethane: 70/30) and thenrecrystallized from a petroleum ether/dichloromethane mixture.

0.033 g of complex is thus obtained in the form of pink crystals, whichcorresponds to a yield of 66%.

The characteristics of the complex are as follows:

-   -   M=616.85;    -   R_(f)=0.50 (petroleum ether/CH₂Cl₂: 70/30);

¹H NMR (CDCl₃): 1.17 (t, 6H, CH₃), 3.66 (m, 4H, CH₂), 7.46 (m, 6H,H₈+H₆), 8.10 (m, 4H, H₇).

¹³C NMR (CDCl₃): 12.6 (CH₃), 44.5 (CH₂), 128.6 and 129.5 (C₆ and C₇),132.2 (C₈), 138.2 (C₅), 200.0 (NCS₂), 225.7 (CS₃).

Infrared (KBr disc): 2 952 (m), 2 915 (m), 2 854 (m), 1 504 (s), 1 499(m), 1 458 (m), 1 440 (m), 1 376 (w), 1 274 (m), 1 207 (m), 1 180 (w), 1148 (m), 1 074 (w), 1 001 (m), 999 (s, ν_(C═S)) 904 (s), 756 (s), 731(m), 683 (s).

EXAMPLE 11 Preparation ofbis(trithioperoxybenzoato)-([4-(2-methoxyphenyl)piperazin-1-ylethyl]dithio-carbamato)technetium(III)

In this example, the same procedure as in Example 10 is followed forpreparing this technetium complex, using, instead of sodiumdiethyldithiocarbamate, the dithiocarbamate of formula (VII):

A biological molecule, 1-(2-methoxyphenyl)piperazine, which has a highaffinity for some receptors located on the neurotransmitters, is thusintroduced into the complex.

The dithiocarbamate of formula (VII) is prepared in the following way.

The starting material is 2-bromoethylamine and the final salt isobtained in four stages:

-   -   protection of the primary amine;    -   introduction of the 1-(2-methoxyphenyl)piperazine;    -   deprotection of the amine; and    -   formation of the dithiocarbamate functional group.

a) Protection of 2-bromoethylammonium bromide

This reaction corresponds to the following scheme:

14 mmol (2.87 g) of 2-bromoethylammonium bromide 1 and 14 mmol (1.95 ml,1.42 g) of triethylamine are dissolved with stirring in 100 ml ofdichloromethane in a 150 ml two-necked flask. 10 mmol (1.51 g) ofpara-nitrobenzaldehyde 2 are added to the solution and the mixture iskept stirred overnight.

The solvent is evaporated and the resulting yellow solid is taken up in50 ml of dichloromethane and 50 ml of water. The organic phase isextracted with 3×25 ml of dichloromethane and washed with 3×25 ml ofwater, then dried over magnesium sulphate and concentrated under vacuum.2.16 g of yellow solid 3 are obtained. The yield is 80%.

The characteristics of the product 3 are as follows:

¹H NMR (CDCl₃) δ in ppm: 3.74 (t, 2H, H₇, J₆₋₇=6.0 Hz), 4.10 (td, 2H,H₆, J₅₋₆=1.2 Hz), 7.94 (m, 2H, H₃), 8.29 (m, 2H, H₂, J₂₋₃=8.8 Hz), 8.39(m, 1H, H₅, J₅₋₆=1.2 Hz).

¹³C NMR (CDCl₃) δ in ppm: 32.0 (C₇), 62.1 (C₆), 123.5 and 128.9 (C₂ andC₃), 140.8 and 148.9 (C₁ and C₄), 160.6 (C₅).

Infrared spectrum (ν in cm⁻¹): 3 100-3 075 (w, aromatic CH), 2 882-2 827(w, aliphatic CH), 1 645 (m, C═N), 1 603 (m, C═C), 1 523 (s, NO₂), 1 424(w, CH₂), 1 342 (s, NO₂), 1 266 (m, C—N), 567 (w, C—Br).

b) Introduction of the 1-(2-methoxyphenyl)piperazine

This reaction corresponds to the following scheme:

12.02 mmol (2.31 g) of 1-(2-methoxyphenyl)piperazine 4 and 12.02 mmol(1.21 g, 1.68 ml) of triethylamine are dissolved in 100 ml ofdichloromethane in a 100 ml round-bottomed flask. 8.02 mmol (2.06 g) ofthe Schiff base 3 are added to the solution with stirring. The mixtureis kept stirred at ambient temperature overnight.

The solvent is evaporated and the yellow residue obtained is taken up in50 ml of dichloromethane and 50 ml of water. The organic phase isextracted with 3×20 ml of dichloromethane and washed with 3×20 ml ofwater, then dried over magnesium sulphate and concentrated under vacuum.The residue obtained is dissolved in 30 ml of ether and the resultingpale yellow solid 5 (1.79 g) is filtered off and washed with ether. Theyield is 60%.

The characteristics of the product 5 are as follows:

¹H NMR (CDCl₃) δ in ppm: 2.81 (m, 6H, H₇ and H₈), 3.12 (m, 4H, H₉), 3.88(s, 3H, H₁₆), 3.89 (m, 2H, H₆), 6.94 (m, 4H, aromatic H), 7.91 (m, 2H,H₃, J₂₋₃=8.8 Hz), 8.28 (m, 2H, H₂), 8.41 (m, 1H, H₅).

¹³C NMR (CDCl₃) δ in ppm: 50.2 and 53.4 (C₈ and C₉), 55.0 (C₁₆), 58.3and 59.0 (C₆ and C₇), 110.8, 117.8, 120.6 and 122.6 (C₁₁ to C₁₄), 123.5and 128.4 (C₂ and C₃), 140.9 and 148.7 (C₁ and C₄), 141.3 and 151.9 (C₁₀and C₁₅), 159.2 (C₅).

Infrared spectrum (ν in cm⁻¹): compound 5: 2 944 (m, CH₃), 2 811 (m,CH₂), 1 648 (m, C═N), 1 601 (m, C═C), 1 522 (s, NO₂), 1 458 (m, CH₂,CH₃), 1 342 (s, NO₂), 1 239 (m, C—O).

c) Deprotection of the Amine According to the Following Reaction Scheme

4.34 mmol (1.60 g) of the product 5 are dissolved in 30 ml ofdichloromethane in a 100 ml round-bottomed flask. 13 ml of a molarhydrochloric acid solution are added with stirring to the solution.Stirring is then maintained for 2 hours at ambient temperature. Theaqueous phase is extracted with 3×10 ml of water and neutralized with 13ml of a molar sodium hydroxide solution. The organic phase is taken upin 3×10 ml of dichloromethane, then washed with 3×5 ml of water, driedover magnesium sulphate and concentrated under vacuum. After evaporatingthe solvent, 0.53 g of a yellow oil 7 are obtained, which corresponds toa yield of 51%.

The characteristics of the product 7 are as follows:

¹H NMR (CDCl₃) δ in ppm: 2.51 (t, 2H, H₂, J₁₋₂=6.1 Hz), 2.67 (m, 4H,H₃), 2.85 (t, 2H, H₁, J₁₋₂=6.1 Hz), 3.10 (m, 4H, H₄), 3.86 (m, 3H, H₁₁),6.93 (m, 4H, aromatic H).

¹³C NMR (CDCl₃) δ in ppm: 38.2 (C₁), 50.3 and 53.1 (C₃ and C₄), 55.0(C₁₁), 60.6 (C₂), 110.8, 117.8, 120.6 and 122.5 (C₆ to C₉), 141.0 and152.0 (C₅ and C₁₀).

d) Formation of the Dithiocarbamate Functional Group According to theFollowing Reaction Scheme

2.25 mmol (0.53 g) of the amine 7 are dissolved in 2 ml of water in a100 ml two-necked flask. 10 ml of an aqueous sodium hydroxide solution(2.60 mmol) are added to the solution, followed by 12 ml of acetone, andthe resulting mixture is stirred until a clear solution is obtained.2.80 mmol (0.21 g, 0.17 ml) of carbon disulphide 8 are added dropwiseand with stirring to the mixture. The solution is cooled using an icebath and maintained at low temperature (with an ice bath) for 5 hoursand with stirring, and then the mixture is placed at 0° C. overnight.The solvent is subsequently evaporated and the residue obtained iswashed with ether. 0.48 g of product 8 is obtained, i.e. a yield of 64%.

The characteristics of the thiocarbamate 8 are as follows:

¹H NMR (CDCl₃) δ in ppm: 2.63 (m, 6H, H₂ and H₃), 2.98 (s, 4H, H₄), 3.67(t, 2H, H₁, J₁₋₂=6.8 Hz), 3.76 (s, 3H, H₁₁), 7.01 (m, 4H, aromatic H).

¹³C NMR (CDCl₃) δ in ppm: 50.2 and 52.8 (C₃ and C₄), 55.0 (C₁₁), 56.2(C₂), 110.8, 117.8, 120.6 and 122.8 (C₆ to C₉), 151.9 (C₅-C₁₀).

Infrared spectrum (ν in cm⁻¹): 3 392 (NH), 2 939 (w, CH₃), 2 829 (w,CH₂), 1 498 (s, NH), 1 458 (m, C═C), 1 377 (w, CH₂, CH₃), 1 234 (s,C—O), 1 115 (m, C═S).

Sodium 2-[4-(2-methoxyphenyl)piperazin-1-yl]ethyl-dithiocarbamate isobtained with a good yield.

EXAMPLE 12 Preparation of a dithiocarbamate Comprising Biotin

Biotin is a vitamin present at a low concentration in the blood whichcan be used to diagnose or treat certain tumours (in particular, tumoursof the abdomen). The method used can consist in injecting, into thebody, an antibody to which has been attached a molecule specific for asubstrate, in this instance avidin, which has a high affinity forbiotin. These antibodies become located at the tumour. Thebiotin-comprising technetium complex is then injected into the body andwill become located preferentially on the antibodies introduced above,which makes possible visualization of the tumour.

The dithiocarbamate used for the preparation of the complex correspondsto the following formula:

The starting material is the primary amine 1-(2-aminoethyl)piperazineand stages analogous to those described in Example 11 are carried out.

a) Protection of the Primary Amine

14 mmol (1.81 g, 1.84 ml) of 1-(2-aminoethyl)piperazine are dissolved in100 ml of dichloromethane with stirring in a 150 ml two-necked flask. 10mmol (1.51 g) of para-nitrobenzaldehyde are added to the solution andthe mixture is kept stirred overnight at ambient temperature. Thesolvent is evaporated and the orange solid obtained is taken up in 50 mlof dichloromethane and 50 ml of water. The organic phase is extractedwith 3×25 ml of dichloromethane and then washed with 3×25 ml of water,dried over magnesium sulphate and concentrated under vacuum. An orangesolid is recovered (2.00 g, i.e. a yield of 76% ).

The characteristics of this product are as follows:

¹H NMR (CDCl₃) δ in ppm: 2.55 (m, 4H, H₂), 2.72 (m, 2H, H₃, J₃₋₄=7.0Hz), 2.91 (m, 4H, H₁, J₁₋₂=4.8 Hz), 3.84 (m, 2H, H₄), 7.89 (m, 2H; H₇),8.27 (m, 2H, H₈), 8.38 (m, 1H, H₅, J₄₋₅=1.3 Hz).

¹³C NMR (CDCl₃) δ in ppm: 45.7 and 54.4 (C₁ and C₂), 59.1 (C₄), 123.5and 128.4 (C₇ and C₈), 141.3 and 148.6 (C₆ and C₉), 159.2 (C₅).

b) Formation of the Sodium Dithiocarbamate Salt

7.63 mmol (2.0 g) of the product obtained in a) are dissolved in 100 mlof dichloromethane in a 150 ml two-necked flask. 12 mmol (0.48 g) ofsodium hydroxide are added to the solution with stirring. The mixture iscooled to −15° C. using a bath of liquid nitrogen and 11 mmol (0.84 g,0.66 ml) of carbon disulphide are added dropwise to the solution withstirring. After returning to ambient temperature, the mixture is stirredovernight. The precipitate obtained is washed with 50 ml ofdichloromethane and then 50 ml of ether and filtered off. It isdissolved in 100 ml of a dichloromethane/water (1:1) mixture and theaqueous phase is extracted and concentrated under vacuum. A brown solidis obtained.

c) Deprotection of the Amine

The solid obtained at the end of stage b) is dissolved in 50 ml ofdichloromethane and 20 ml of water. 8 mmol (0.32 g) of sodium hydroxideare added to the solution and stirring is maintained for one hour. Theaqueous phase is extracted with 20 ml of water and concentrated undervacuum. A brown solid is obtained (1.57 g, yield=69% ).

It corresponds to the formula:

¹H NMR (D₂O) δ in ppm: 2.41 (m, 2H, H₃), 2.49 (t, 4H, H₂, J₁₋₂=5.2 Hz),2.69 (m, 2H, H₄), 4.26 (t, 4H, H₁, J₁₋₂=5.1 Hz).

¹³C NMR (D₂O) δ in ppm: 36.9 (C₄), 49.9 and 51.6 (C₁ and C₂), 58.8 (C₃),208.1 (C═S).

d) Coupling of the Biotin According to the Following Reaction Scheme

The biotin is first of all esterified with N-hydroxysuccinimide and thenreacted with the thiocarbamate obtained in stage c) in dimethylformamide(DMF). The biotin-comprising dithiocarbamate thus obtained is insolublein this solvent and can be recovered.

EXAMPLE 13 Preparation of the pyrrolidyldithio-carbamate

In this example, the same procedure as in Example 3 is followed forpreparing this dithiocarbamate, using:

-   -   0.025 mol (1.78 g, 2 ml) of pyrrolidine instead of the        piperidine;    -   0.030 mol of NaOH (1.20 g); and    -   0.026 mol (1.98 g, 1.6 ml) of CS₂.

1.94 g of a mixture comprising 37% of sodium pyrrolidyldithiocarbamateand 63% of pyrrolidinium pyrrolidyldithiocarbamate are thus obtained,which mixture has the following characteristics:

¹H NMR: 1.90 (m, 6.8H, H₂ and H₄), 3.18 (m, 2.6H, H₃, J₃₋₄=7.3 Hz), 3.68(m, 4.2H, H₁, J₁₋₂=7.0 Hz).

¹³C NMR: 23.3 (C₄), 25.2 (C₂), 45.2 (C₃), 54.6 (C₁), 202.2 (C═S).

Infrared spectrum (ν in cm⁻¹): 2 943 (m, CH₂), 2 868 (m, CH₂), 1 420 (s,C—N), 1 400 (m, CH₂), 1 160 (m, C═S).

EXAMPLE 14 Preparation of sodium 1-ethylpiperazinyl-dithiocarbamate

In this example, the same procedure as in Example 3 is followed forpreparing this dithiocarbamate, using:

-   -   0.025 mol (2.85 g, 3 ml) of 1-ethylpiperazine instead of the        piperidine;    -   0.030 mol (1.20 g) of NaOH; and    -   0.026 mol (1.98 g, 1.6 ml) of CS₂.

3.11 g of sodium 1-ethylpiperazinyldithiocarbamate are thus obtained,which product exhibits the following characteristics:

¹H NMR: 1.01 (t, 3H, H₄), 2.44 (q, 2H, H₃, J₃₋₄=7.3 Hz), 2.52 (m, 4H,H₂), 4.28 (m, 4H, H₁).

¹³C NMR: 10.0 (C₄), 50.8 (C₃), 49.8 and 59.9 (C₁ and C₂), 202.1 (C═S).

Infrared spectrum (ν in cm⁻¹): 2 969 (w, CH₃), 2 818 (m, CH₂), 1 415 (s,C—N), 1 227 (s, C═S).

References Cited

-   [1] FR-A-2 698 272-   [2] F. Mevellec et al., Inorg. Chem. Comm., 2, 1999, 230-233-   [3] Wei et al., J. Am. Chem. Soc., 1990, 112, 6433-6434-   [4] McConnachie and Stiefel, Inorg. Chem., 1997, 36, 6144-6145-   [5] McConnachie and Stiefel, Inorg. Chem., 1999, 38, 964-972

1-44. (Cancel)
 45. Technetium or rhenium complex of formula (I):[M(R¹CS₃)₂L]  (I) in which M is Tc or Re, R¹ represents an alkyl,cycloalkyl, aralkyl or aryl group which is unsubstituted or substitutedby one or more substituents chosen from halogen atoms, the hydroxylgroup, alkyl groups and alkoxy groups, and L is a dithiolate ligand,with the exception of the ligand of formula R²CS₂ in which R² isidentical to R¹.
 46. Complex according to claim 45, in which L is chosenfrom dithiocarbamate, xanthate, dithiophosphate, dithiophosphonate,dithiophosphinate, dithiocarboxylate, 1,2-dithiolate and 1,2-dithioleneligands.
 47. Complex according to claim 46, in which the ligand L is adithiocarbamate of formula (II):

in which R³ and R⁴, which can be identical or different, represent ahydrogen atom, a C₁ to C₁₀, preferably C₁ to C₅, alkyl group, a C₆ toC₁₀ aryl group or a C₇ to C₁₂ aralkyl group, the alkyl, aryl or aralkylgroups optionally comprising one or more groups chosen from OH, SH,COOH, COOR, NH₂, NHR, NR₂, CONH₂, CONHR, CONR₂, NCSR and SCNR where theR groups, which can be identical or different, represent an alkyl oraryl group, groups capable of reacting with a biological molecule andgroups derived from a biological molecule which are optionally connectedto the alkyl, aryl or aralkyl group via a spacer, or in which R³ and R⁴form, together with the nitrogen atom to which they are bonded, aheterocycle having from 3 to 5 carbon atoms optionally comprisinganother heteroatom chosen from O, S and N, this heterocycle beingunsubstituted or substituted by one or more C₁ to C₁₀ alkyl, C₆ to C₁₀aryl or C₇ to C₁₂ aralkyl groups, the alkyl, aryl or aralkyl groupsoptionally comprising one or more groups chosen from OH, SH, COOH, COOR,NH₂, NHR, NR₂, CONH₂, CONHR, CONR₂, NSCR and SCNR where the R groups,which can be identical or different, represent an alkyl or aryl group,groups capable of reacting with a biological molecule and groups derivedfrom a biological molecule which are optionally connected to the alkyl,aryl or aralkyl group via a spacer.
 48. Complex according to claim 45,in which the ligand L is more electronegative than the groups R¹CS₃. 49.Complex according to claim 45, in which R¹ is the phenyl group. 50.Complex according to claim 45, in which R¹ is a linear or branched C₁ toC₁₂ alkyl group.
 51. Complex according to claim 45, in which R¹represents the naphthyl group or the naphthyl group substituted by agroup chosen from alkyl groups, alkoxy groups and halogen atoms. 52.Complex according to claim 45, in which R¹ is chosen from phenyl groupssubstituted by one or more methyl, ethyl, propyl, butyl, methoxy, ethoxyand/or hydroxyl groups and/or by one or more fluorine, chlorine, bromineand/or iodine atoms.
 53. Complex according to claim 45, in which R¹ isthe cyclohexyl, benzyl or phenethyl group.
 54. Complex according toclaim 47, in which R³ and R⁴ are a methyl, ethyl or ethoxy group. 55.Complex according to claim 47, in which R³ is the ethyl group and R⁴ isthe hydroxyethyl group.
 56. Complex according to claim 47, in which R³and R⁴ form, with the nitrogen atom to which they are bonded, apiperidine, pyrrolidine, pyridine, ethylpiperazine or morpholine ring.57. Complex according to claim 47, in which R³ is a hydrogen atom and R⁴represents the group of formula (III):

in which n is an integer ranging from 1 to 6, preferably equal to
 2. 58.Complex according to claim 47, in which R³ and R⁴ form, with thenitrogen atom to which they are bonded, the group of formula (X):

in which n is an integer ranging from 1 to 6, preferably equal to
 2. 59.Radiopharmaceutical product comprising a complex according to claim 45,in which M is ^(99m)Tc, ¹⁸⁶Re or ¹⁸⁸Re.
 60. Process for the preparationof a technetium or rhenium complex of formula (I):[M(R¹CS₃)₂L]  (I) in which M is Tc or Re, R¹ represents an alkyl,cycloalkyl, aralkyl or aryl group which is unsubstituted or substitutedby one or more substituents chosen from halogen atoms, the hydroxylgroup, alkyl groups and alkoxy groups, and L is a dithiolate ligand,with the exception of the ligand of formula R²CS₂ in which R² isidentical to R¹, which comprises the following stages: reacting a saltof formula (IVa) or (IVb):(MO₄)⁻Z_(a) ⁺  (IVa)[MOCl₄]⁻Z_(a) ⁺  (IVb) in which M is as defined above and Z_(a) ⁺ is apharmaceutically acceptable cation, with a reducing agent, and adding,to the reaction mixture, a dithiocarboxylate of formula (V):(R¹CS₂)⁻Z_(b) ⁺  (V) in which R¹ is as defined above and Z_(b) ⁺represents a pharmaceutically acceptable cation, and a salt L⁻X⁺ where Lis as defined above and X⁺ is a cation chosen from sodium and potassium.61. Process for the preparation of a technetium or rhenium complex offormula (I):[M(R¹CS₃)₂L]  (I) in which M is Tc or Re, R¹ represents an alkyl,cycloalkyl, aralkyl or aryl group which is unsubstituted or substitutedby one or more substituents chosen from halogen atoms, the hydroxylgroup, alkyl groups and alkoxy groups, and L is a dithiolate ligand,with the exception of the ligand of formula R²CS₂ in which R² isidentical to R¹, which comprises bringing a technetium or rheniumcomplex of formula (VI):[M(R¹CS₃)₂(R¹CS₂)]  (VI) in which M and R¹ are as defined above, intocontact with a salt L⁻X⁺, where L is as defined above and X⁺ is a cationchosen from sodium and potassium, in order to exchange the ligand R¹CS₂with the ligand L.
 62. Process according to claim 60, in which theligand L comprises a group capable of reacting with a biologicalmolecule and in that the process comprises an additional stageconsisting in reacting the complex formed with a biological molecule inorder to attach it to the ligand L.
 63. Process according to claim 61,in which the complex of formula (VI):[M(R¹CS₃)₂(R¹CS₂)]  (VI) is prepared by carrying out the followingstages: reacting a salt of formula (IVa):(MO₄)⁻Z_(a) ⁺  (IVa) in which M is as defined above and Z_(a) ⁺ is apharmaceutically acceptable cation, with a reducing agent, and adding,to the reaction mixture, a dithiocarboxylate of formula (V):(R¹CS₂)⁻Z_(b) ⁺  (V) in which R¹ is as defined above and Z_(b) ⁺represents a pharmaceutically acceptable cation.
 64. Process accordingto claim 60, in which Z_(b) ⁺ represents a cation chosen from MgX⁺,where X is a halogen atom, an alkali metal ion, a quaternary ammoniumcation or the piperidinium cation.
 65. Process according to claim 60, inwhich the reducing agent is a tin salt in combination with a complexingagent, or an HCl/phosphine mixture.
 66. Process according to claim 65,in which the tin salt is tin chloride and the complexing agent iscalcium gluconate, 1,2-diaminopropane-N,N,N′,N′-tetraacetic acid and adithiocarbazate DTCZ.
 67. Process according to claim 65, in which thephosphine is triphenylphosphine or sodiumtriphenylphosphine-tri-meta-sulphonate.
 68. Process according to claim60, in which the salt L⁻X⁺ corresponds to the formula (XI):

in which R³ and R⁴, which can be identical or different, represent ahydrogen atom, a C₁ to C₁₀, preferably C₁ to C₅, alkyl group, a C₆ toC₁₀ aryl group or a C₇ to C₁₂ aralkyl group, the alkyl, aryl or aralkylgroups optionally comprising one or more groups chosen from OH, SH,COOH, COOR, NH₂, NHR, NR₂, CONH₂, CONHR, CONR₂, NCSR and SCNR where theR groups, which can be identical or different, represent an alkyl oraryl group, groups capable of reacting with a biological molecule andgroups derived from a biological molecule which are optionally connectedto the alkyl, aryl or aralkyl group via a spacer, or in which R³ and R⁴form, together with the nitrogen atom to which they are bonded, aheterocycle having from 3 to 5 carbon atoms optionally comprisinganother heteroatom chosen from O, S and N, this heterocycle beingunsubstituted or substituted by one or more C₁ to C₁₀ alkyl, C₆ to C₁₀aryl or C₇ to C₁₂ aralkyl groups, the alkyl, aryl or aralkyl groupsoptionally comprising one or more groups chosen from OH, SH, COOH, COOR,NH₂, NHR, NR₂, CONH₂, CONHR, CONR₂, NSCR and SCNR where the R groups,which can be identical or different, represent an alkyl or aryl group,groups capable of reacting with a biological molecule and groups derivedfrom a biological molecule which are optionally connected to the alkyl,aryl or aralkyl group via a spacer.
 69. Kit for the preparation of aradiopharmaceutical product comprising a complex of formula (I):[M(R¹CS₃)₂L]  (I) in which M is ^(99m)Tc, 186Re or 188Re, R¹ representsan alkyl, cycloalkyl, aralkyl or aryl group which is unsubstituted orsubstituted by one or more substituents chosen from halogen atoms, thehydroxyl group, alkyl groups and alkoxy groups, and L is a dithiolateligand, with the exception of the ligand of formula R²CS₂ in which R² isidentical to R¹, which comprises: a first bottle comprising a tin saltin combination with a complexing agent, or a phosphine and hydrochloricacid, a second bottle comprising a dithiocarboxylate of formula(R¹CS₂)⁻Z_(b) ⁺ in which R¹ is as defined above and Z_(b) ⁺ represents apharmaceutically acceptable cation, and a third bottle comprising a salt^(L) ⁻X⁺ where L is as defined above and X⁺ is a cation chosen fromsodium and potassium.
 70. Kit for the preparation of aradiopharmaceutical product comprising a complex of formula (I):[M(R¹CS₃)₂L]  (I) in which M is ^(99m)Tc, ¹⁸⁶Re or ¹⁸⁸Re, R¹ representsan alkyl, cycloalkyl, aralkyl or aryl group which is unsubstituted orsubstituted by one or more substituents chosen from halogen atoms, thehydroxyl group, alkyl groups and alkoxy groups, and L is a dithiolateligand, with the exception of the ligand of formula R²CS₂ in which R² isidentical to R¹, which comprises: a first bottle comprising a tin saltin combination with a complexing agent, or a phosphine and hydrochloricacid, and a second bottle comprising a dithiocarboxylate of formula(R¹CS₂)⁻Z_(b) ⁺ in which R¹ is as defined above and Z_(b) ⁺ represents apharmaceutically acceptable cation, and a salt L⁻X⁺ where L is asdefined above and X⁺ is a cation chosen from sodium and potassium. 71.Kit according to claim 69, in which the first bottle comprises tinchloride SnCl₂.2H₂O in combination with a complexing agent chosen fromcalcium gluconate, 1,2-diaminopropane-N,N,N′,N′-tetraacetic acid and adithiocarbazate DTCZ.
 72. Kit according to claim 69, in which the firstbottle comprises triphenylphosphine or sodiumtriphenylphosphine-tri-meta-sulphonate, and hydrochloric acid.
 73. Kitaccording to claim 69, which additionally comprises a bottle comprisinga biological molecule.
 74. Kit according to claim 69, in which the saltL⁻X⁺ is a dithiocarbamate of formula (XI):

in which R³ and R⁴, which can be identical or different, represent ahydrogen atom, a C₁ to C₁₀, preferably C₁ to C₅, alkyl group, a C₆ toC₁₀ aryl group or a C₇ to C₁₂ aralkyl group, the alkyl, aryl or aralkylgroups optionally comprising one or more groups chosen from OH, SH,COOH, COOR, NH₂, NHR, NR₂, CONH₂, CONHR, CONR₂, NCSR and SCNR where theR groups, which can be identical or different, represent an alkyl oraryl group, groups capable of reacting with a biological molecule andgroups derived from a biological molecule which are optionally connectedto the alkyl, aryl or aralkyl group via a spacer, or in which R³ and R⁴form, together with the nitrogen atom to which they are bonded, aheterocycle having from 3 to 5 carbon atoms optionally comprisinganother heteroatom chosen from O, S and N, this heterocycle beingunsubstituted or substituted by one or more C₁ to C₁₀ alkyl, C₆ to C₁₀aryl or C₇ to C₁₂ aralkyl groups, the alkyl, aryl or aralkyl groupsoptionally comprising one or more groups chosen from OH, SH, COOH, COOR,NH₂, NHR, NR₂, CONH₂, CONHR, CONR₂, NSCR and SCNR where the R groups,which can be identical or different, represent an alkyl or aryl group,groups capable of reacting with a biological molecule and groups derivedfrom a biological molecule which are optionally connected to the alkyl,aryl or aralkyl group via a spacer.
 75. Kit according to claim 74, inwhich R³ is a hydrogen atom and R⁴ represents the group of formula(III):

in which n is an integer ranging from 1 to 6, preferably equal to
 2. 76.Kit according to claim 74, in which R³ and R⁴ form, with the nitrogenatom to which they are bonded, the group of formula (X):

in which n is an integer ranging from 1 to 6, preferably equal to
 2. 77.Process according to claim 61, in which the ligand L comprises a groupcapable of reacting with a biological molecule and in that the processcomprises an additional stage consisting in reacting the complex formedwith a biological molecule in order to attach it to the ligand L. 78.Process according to claim 63, in which Z_(b) ⁺ represents a cationchosen from MgX⁺, where X is a halogen atom, an alkali metal ion, aquaternary ammonium cation or the piperidinium cation.
 79. Processaccording to claim 63, in which the reducing agent is a tin salt incombination with a complexing agent, or an HCl/phosphine mixture. 80.Process according to claim 79, in which the tin salt is tin chloride andthe complexing agent is calcium gluconate,1,2-diaminopropane-N,N,N′,N′-tetraacetic acid and a dithiocarbazateDTCZ.
 81. Process according to claim 79, in which the phosphine istriphenylphosphine or sodium triphenylphosphine-tri-meta-sulphonate. 82.Process according to claim 61, in which the salt L⁻X⁺ corresponds to theformula (XI):

in which R³ and R⁴, which can be identical or different, represent ahydrogen atom, a C₁ to C₁₀, preferably C₁ to C₅, alkyl group, a C₆ toC₁₀ aryl group or a C₇ to C₁₂ aralkyl group, the alkyl, aryl or aralkylgroups optionally comprising one or more groups chosen from OH, SH,COOH, COOR, NH₂, NHR, NR₂, CONH₂, CONHR, CONR₂, NCSR and SCNR where theR groups, which can be identical or different, represent an alkyl oraryl group, groups capable of reacting with a biological molecule andgroups derived from a biological molecule which are optionally connectedto the alkyl, aryl or aralkyl group via a spacer, or in which R³ and R⁴form, together with the nitrogen atom to which they are bonded, aheterocycle having from 3 to 5 carbon atoms optionally comprisinganother heteroatom chosen from O, S and N, this heterocycle beingunsubstituted or substituted by one or more C₁ to C₁₀ alkyl, C₆ to C₁₀aryl or C₇ to C₁₂ aralkyl groups, the alkyl, aryl or aralkyl groupsoptionally comprising one or more groups chosen from OH, SH, COOH, COOR,NH₂, NHR, NR₂, CONH₂, CONHR, CONR₂, NSCR and SCNR where the R groups,which can be identical or different, represent an alkyl or aryl group,groups capable of reacting with a biological molecule and groups derivedfrom a biological molecule which are optionally connected to the alkyl,aryl or aralkyl group via a spacer.
 83. Kit according to claim 70, inwhich the first bottle comprises tin chloride SnCl₂.2H₂O in combinationwith a complexing agent chosen from calcium gluconate,1,2-diaminopropane-N,N,N′,N′-tetraacetic acid and a dithiocarbazateDTCZ.
 84. Kit according to claim 70, in which the first bottle comprisestriphenylphosphine or sodium triphenylphosphine-tri-meta-sulphonate, andhydro-chloric acid.
 85. Kit according to claim 70, which additionallycomprises a bottle comprising a biological molecule.
 86. Kit accordingto claim 70, in which the salt L⁻X⁺ is a dithiocarbamate of formula(XI):

in which R³ and R⁴, which can be identical or different, represent ahydrogen atom, a C₁ to C₁₀, preferably C₁ to C₅, alkyl group, a C₆ toC₁₀ aryl group or a C₇ to C₁₂ aralkyl group, the alkyl, aryl or aralkylgroups optionally comprising one or more groups chosen from OH, SH,COOH, COOR, NH₂, NHR, NR₂, CONH₂, CONHR, CONR₂, NCSR and SCNR where theR groups, which can be identical or different, represent an alkyl oraryl group, groups capable of reacting with a biological molecule andgroups derived from a biological molecule which are optionally connectedto the alkyl, aryl or aralkyl group via a spacer, or in which R³ and R⁴form, together with the nitrogen atom to which they are bonded, aheterocycle having from 3 to 5 carbon atoms optionally comprisinganother heteroatom chosen from O, S and N, this heterocycle beingunsubstituted or substituted by one or more C₁ to C₁₀ alkyl, C₆ to C₁₀aryl or C₇ to C₁₂ aralkyl groups, the alkyl, aryl or aralkyl groupsoptionally comprising one or more groups chosen from OH, SH, COOH, COOR,NH₂, NHR, NR₂, CONH₂, CONHR, CONR₂, NSCR and SCNR where the R groups,which can be identical or different, represent an alkyl or aryl group,groups capable of reacting with a biological molecule and groups derivedfrom a biological molecule which are optionally connected to the alkyl,aryl or aralkyl group via a spacer.
 87. Kit according to claim 86, inwhich R³ is a hydrogen atom and R⁴ represents the group of formula(III):

in which n is an integer ranging from 1 to 6, preferably equal to
 2. 88.Kit according to claim 86, in which R³ and R⁴ form, with the nitrogenatom to which they are bonded, the group of formula (X):

in which n is an integer ranging from 1 to 6, preferably equal to 2.